lighting conditions; sunrise is 6:18a, so the collision occurred before that?

This is just a general observation about this sort of intersection:
There are numerous challenges for a bicyclist there — many bicyclists will choose ride on the sidewalk, and will ride without regard to direction (here’s one on google street view!). ADOT has designed the intersection with EIGHT high speed ramps. Fully four of these are free-flowing thru a crosswalk. The other four are also high speed, though controlled with signals. That means a pedestrian, or a bicyclist acting as pedestrian, traversing the 500 or so feet along 24th street will be going through 4 crosswalks, facing a significant wait time at two of them — a motorist will traverse this intersection on average with a wait time of perhaps a minute. A pedestrian will face significantly longer due to both traffic and waiting (twice!) for a “demand” ped signal phase; plus having to scamper across the other two crosswalks with freely flowing high-speed traffic crossing it. Many peds won’t bother waiting for those long demand cycles.

This intersection was identified in ADOT’s 2012 Bicycle Safety Action Plan as a high priority intersection because of a high frequency of bike-MV crashes there. See appendix A2 / location 26H.

A newer/later azcentral.com covers (with some background info, but no new details) both this fatality and another bicyclist fatality that happened elsewhere in Phx on the same day. The story (accurately) mentions that 29 Arizona bicyclists were killed in traffic crashes in 2015; it, however, fails to give any context, e.g. in that same year there were a total of 894 people killed in traffic collisions in Arizona, most of them motorists. Those figures are unadjusted, but it does give a sense of the magnitude of the overall traffic problem, and that bicyclist-MV is but a small part.

The story makes an apparent misquote by saying (my emphasis):

Countless more bicyclists have been seriously injured, a number that remains elusive because only an estimated 10 percent of bicycle crashes causing serious injuries are reported to the police, data from pedbikeinfo.org revealed.

research into hospital records shows that only a fraction of bicycle crashes causing injury are ever recorded by the police, possibly as low as ten percent

In other words, the azcental story added the “serious” when in fact the vast majority of bicyclist injuries are minor. There’s another parallel factor, which is that the large majority of bicyclist injuries do not involve any motor vehicle, they are things like “simple falls”, and are therefore “not counted” as there is, by definition, no Crash Report; there’s nothing nefarious going on. There are studies that correlate hospital records with police crash reports to back up the numbers:

Results show that 70 percent of the reported bicycle injury events … did not involve a motor vehicle